摘要
长园带状杂岩体主要由长园石英二长闪长岩、官山石英二长岩、沙峪斑状花岗岩和西后峪花岗岩4个侵入体构成。长园石英二长闪长岩富镁贫铁,准铝质,属高钾钙碱性系列;具弱的Eu负异常,Sr/Y值较高,是中性埃达克质岩。官山石英二长岩富碱富镁,Sr/Y和（La/Yb）N值高,具弱的Eu负异常,是典型的＂C型埃达克岩＂。沙峪和西后峪花岗岩属高钾钙碱性系列岩石,稀土元素总量低,具负Eu异常。长园石英二长闪长岩和官山石英二长岩是高Sr的基性原始岩浆在中等压力（0.8～1.2GPa）条件下分离结晶的产物。沙峪斑状花岗岩和西后峪花岗岩则是由幔源岩浆与地壳岩石发生相互作用的产物。长园带状杂岩体的实例表明,埃达克质岩起源或形成的压力可以相对较低（〈1.2 GPa）。
The Changyuan zoned pluton is composed by Changyuan quartz monzodiorite,Guanshan quartz monzonite,Shayu porphyritic granite,and the Xihouyu granite successively from the periphery to the core. Changyuan quartz monzodiorite is magnesian metaluminous high-potassic calc-alkaline rock,with weak Eu negative anomalies and high Sr/Y ratio. Therefore,Changyuan quartz monzodiorite belongs to the intermediate adakitic rocks. The magnesian Guanshan quartz monzonite,with high Sr/Y and（ La/Yb）Nratios and weak Eu negative anomalies is also a typical ＂C-tpye adakite＂. Shayu and Xihouyu granite belong to the magnesian peraluminous high-potassic calc-alkaline rock. They have low content of rare earth elements and weak Eu negative anomalies. Changyuan quartz monzodiorite and Guanshan quartz monzonite were originated by the fractional crystallization of mafic magma with high Sr content under intermediate pressure（ 0. 8- 1. 2 GPa）condition. Meanwhile,Shayu porphyritic granite and Xihouyu granite were produced by the double-diffusive interaction between the mantle derived magma and the crustal wall-rocks. The Changyuan zoned pluton is an typical example that the adakitic rocks can be generated within the relatively low pressure（ 〈1. 2 GPa） condition.
出处
《矿物岩石地球化学通报》
CAS
CSCD
北大核心
2015年第4期820-829,共10页
Bulletin of Mineralogy, Petrology and Geochemistry
基金
中央高校基本科研业务费专项资金(2652013021)
